DEVICE FOR HOLDING DOWN THE STITCHES BEING FORMED IN A FLAT KNITTING MACHINE

Abstract: The device is mounted on a flat knitting machine that includes a carriage (20) mobile horizontally over at least one needle bed (1) featuring grooves (2) inside which there are inserted needles that can slide. The needle bed (1) also features a plurality of slits (4), parallel to, and ordinately set among, the grooves (2), inside which there are inserted plate means (6) that form a kind of comb that cooperates to the formation of the stitches. Beside these means there are located pressing means (16) independent therefrom and mounted in a way so that they can swing, so that when they are set in a lowered position, they hold in place the stitches being formed on the needle bed (1).

Description: DEVICE FOR HOLDING DOWN THE STITCHES BEING FORMED IN A FLAT KNITTING MACHINE TECHNICAL FIELD The present invention relates to the techni¬ cal filed concerning knitting machines . BACKGROUND ART Various flat knitting machines are known, which include a pair of needle beds and a carriage that is mobile along a horizontal path over the needle beds . The carriage has the task of setting into operation the needles, that are inserted into grooves of the needle beds, in accordance with a pre-fixed program. The carriage also supplies the group of operating needles with a thread that is fed by various reels . The needle beds of the knitting machine feature a kind of comb situated in correspondence with the region where the stitches are made, and the needles operate among the teeth of this comb. Among these teeth there is formed a trans- verse member that defines a geometrical line along which the stitches are made. In the above mentioned machines the necessity arises of holding the stitches being formed in a lowered position to prevent them from being pulled up by the needles that are moving upwards. The needles are in fact raised upward both for the formation of the stitches, and for transfer¬ ring the stitches from one needle bed to the other one. For this purpose the traditional knitting machines are generally equipped with a so-called stitch retaining device, that has the task of hold¬ ing down the stitches that have just been formed. This stitch retaining device though operates downstream of the group of needles set into opera- tion, so that it does not assure an optimal effect. According to another configuration, hook means are used in order to grip the stitches just formed, as it is disclosed by the US-A-4.697.439 owned by the Applicant. According to another solution, auxiliary swinging needle beds are mounted outside of the needle beds destined to the formation of the stit¬ ches, and are equipped with a kind of comb designed to insert among the teeth of these last needle beds . It must be also noted that the transverse member along which the stitches are made and then held down, is presently made integral with the needle bed, through proper mechanical working. This fact does not allow for obtaining per- fectly smoothed surfaces, and consequently the friction with the fabric increases. Furthermore, the teeth of the needle beds, also made integral with the needle beds through mechanical working, apparently are those parts which more often get broken or damaged. In case of breaking it is necessary to flush a portion of the needle bed and to report a substi- tutive part thereon, this part also being obtained by mechanical working. All this results in complica- tions and high costs. DISCLOSURE OF THE INVENTION The object of the present invention is to propose a device that holds down the stitches in an optimal way while being formed, that operates in correspondence with the region where the stitches are formed . Another object of the present invention is to give assurance about working of the device as well as to allow for an easy maintenance for the region destined to the formation of the stitches . The above mentioned object are achieved by means of a device for holding down the stitches being formed, that includes: a plurality of plate means which form a kind of comb that cooperates to form the stitches, these plate means being removably inserted into related slits made in the needle bed and parallel to and ordinate- ly set among the grooves for the needle; a plurality of pressing means respectively located side by side near the plate means and inserted into the slits, these pressing means being independent from the plate means and mounted in such a way that they are swingable, so that when they are in lowered position, they hold down the stitches being formed on the needle bed. BRIEF DESCRIPTION OF THE DRAWINGS The characteristic features of the invention are set out in the following, with particular refer- ence to the accompanying drawings, in which: - Fig. 1 shows a plan view of a portion of a knit¬ ting machine needle bed, particularly of the region where the stitches are made; - Fig. 2 shows a cross-section view of the needle bed of Fig. 1, taken along the line II-II; - Fig. 3 shows a side view of a member designed to form the stitches, that is an exploded view with respect to Fig. 2; - Figs. 4 and 5 show the same plan view and cross- section view of the needle bed respectively, with the stitch formation members mounted thereon; - Fig. 6 shows a cross-section view of the needle bed as seen according to a sectional plane parallel to the one of Fig. 5,- - Fig. 7 shows a side view of a stitch pressing means, that is an exploded view of Fig. 6; - Fig. 8 shows the same cross-section view of Fig. 5, with the pressing means already mounted; - Fig. 9 shows a cross-section view taken along the line IX-IX of Fig. 8. BEST MODE OF CARRYING OUT THE INVENTION Having reference to the above mentioned figures, reference numeral 1 indicates the needle bed of a flat knitting machine, particularly the region where the stitches are formed. The needle bed 1 has a plurality of grooves 2 arranged side by side and aimed at receiving and holding respective needles 3. In the needle bed 1, among the grooves 2, there are made slits 4 parallel to the grooves. The slits 4 have their bottoms profiled like a curved line, so that a kind of bowl is defined in each of them. More particularly, the slits 4 have each one a forepart 4a and a rearpart 4b which are narrower that a midportion of the slit, and which are located on a midplane between two subsequent grooves 2. As it clearly appears from Fig. 1, the mid¬ portion extends at one side in such a way that it is asymmetric with respect to the same midplane. The slits join respective underlying notches 5, that are made in the same needle bed 1. The slits 4 are aimed at receiving and hold¬ ing respective shaped plates 6, which have thickness corresponding to the width of the forepart 4a and rearpart 4b of the slits (see Fig. 3) . The plates 6 have each one, at an end, a head 7 that protrudes from the needle bed 1 when the plate is mounted thereonto. The head 7 has a lip 8 designed to grip the needle bed 1, in a region corresponding to the forepart 4a of the related slit (see figures 4 and 5) . The head 7 of each plate 6 has a hole 9, through which a stem 10 passes. The stem 10 has the task of making a stop for the stitches being formed. The plates 6 are bound to the needle bed by means of a rod 11 that passes through respective slots 12, made in a central part of each plate 6, and that lies into corresponding seats 13 made in the needle bed, in correspondence with the notches 5. The plates 6 are also bound to each other by means of a bar 14 that is arranged transversal to them and that is inserted into corresponding open- ings 15 designed to act as a guide therefor. The enlarged midportion of each slit 4 is adapted to hold a pressing means 16, that substanti¬ ally includes another shaped plate (see Fig. 7) . The pressing means 16 features a head 17 that is designed to work beside the head 7 of the adja¬ cent plate 6. The pressing means 16 is swingable, with respect of the plane on which it lies, as indicated by the arrow A in Fig. 8. More precisely, the pressing means 16 can swing about a fulcrum defined by the rod 11 that passes through a recess 18 made in the same pressing means 16. Consequently, the pressing means can be shifted from a raised position to a working lowered position, that is indicated by a dashed line 16a in Fig.8. The swing motion of the pressing means is controlled by a flat cam 19, fastened to the carri¬ age 20 of the machine, that goes in engagement with a butt 21 extending from each one of the pressing means 16. Therefore, when the pressing means 16 are shifted by the carriage 20 to the lowered position, in suitable time relation with operation of the needle 3, they hold the stitches, while being for¬ med, against the stop defined by the stem 10 that passes through the heads 7 of the plates 6. It must be stressed that the pressing means operate in a region where the stitches are formed, taking alternate positions among the needles 3, without any interference with the stitch formation. The pressing means are in fact mounted in a way that they can swing and inserted into the slits 4 which also define a holding seat for the plates 6, that are arranged aside of the respective pressing means . However the pressing means are fully indepen- dent from the plates 6. Moreover, the pressing means are arranged immediately aside of the respective needles 3. INDUSTRIAL APPLICABILITY The industrial applicability of the claimed invention results well clear from the need that exists for stitch retaining devices which must be reliable and effective, and from the advantages that the present invention brings about. The comb that cooperates with the formation of the stitch is made by means of the removable plates 6, and this allows for an easy and cheap replacement operation in case one or more of the operating head 7 get broken or damaged. It must be stressed that this replacement operation does not require mechanical working, but only the replacement of a piece produced in series is necessary, these pieces being easily stored in a spare parts store. Also the cost of the plates is very low in that they are obtained from a metal sheet. However, when the plates are mounted, they are firmly held and locked by the transversal rod 11 and the bar 14, so that the whole assembly is suitably stiff and compact. It must be also noted that the transverse member that defines the geometrical line along which the stitches are formed, includes the stem 10 that passes through the holes 9 of the heads 7 of the plates 6. The stem 10 is made very smooth, so that to reduce as much as possible the friction with the stitches. Moreover, the subject invention has been described, with reference to the enclosed drawings, only as a mere example, not limitative, therefore it is obvious that all the modifications o variants suggested either by practice or the activation and usage thereof are anyway within the following claims .

Claims: CLAIMS 1. Device for holding down the stitches being formed in a flat knitting machine, this machine including a mobile carriage (20) that runs horizontally over a needle bed (1) featuring grooves (2) inside which there are inserted needle (3) that can slide, the said device being characterised in that it includes a plurality of pressing means (16) located inside related slits (4) made in the said needle bed (1) and parallel to, and ordinately set among, the said grooves (2) for the needle (3) , these pressing means being swingable in a manner that, when they are in lowered position, they hold down the stitches being formed on the needle bed (2) . 2. Device for holding down the stitches being formed in a flat knitting machine, this machine including a mobile carriage (20) that runs horizontally over a needle bed (1) featuring grooves (2) inside which there are inserted needle (3) that can slide, the said device being characterised in that it includes: a plurality of plate means (6) which form a kind of comb that cooperates to form the stitches, the said plate means being removably inserted into related slits (4) made in the said needle bed (1) and paral¬ lel to, and ordinately set among, the said grooves (2) for the needle (3) ; a plurality of pressing means (16) respectively located side by side near the said plate means (6) and inserted into the said slits (4) , the said pressing means being independent from the said plate means (6) and mounted in such a way that they are swingable, so that when they are in lowered posi- tion, they hold down the stitches being formed on the needle bed (2) . 3. Device as in claim 2, characterised in that the said plate means (6) feature each at one end a head (7) that protrudes from the said needle bed (1) , when the plate means are mounted thereonto, this head having a lip (8) designed to grip the needle bed (1) in correspondence with a forepart (4a) of the related slit (4) . 4. Device as in claim 3, characterised in that the said head (7) of the said plate means (6) are crossed by a stem (10) designed to make a stop for the stitches being formed. 5. Device as in claim 2, characterised in that the said plate means (6) are bound to the said needle bed (1) by means of a rod (11) that passes through respective slots (12) made in a central part of said plate means (6) , and that lies into corresponding seats (13) made in the said needle bed (1) , the said rod (11) also acting as a fulcrum for the said pressing means (16) . 6. Device as in claim 1 or 2, characterised in that the said pressing means (16) are made to swing by a flat cam (19) fastened to the said carriage (20) of the knitting machine, this flat cam being designed to guide a butt (21) extending from the said press¬ ing means (16) . 7. Device as in claim 2, characterised in that the said pressing means (16) include plates, each having a head (17) and being designed to work aside of a corresponding head (7) of the said plate means (6) . 8. Device as in claim 2, characterised in that each of the said slits (4) has a forepart (4a) and a rearpart (4a) located on the midplane between two of the said grooves (2) , and narrower than a midportion of the slit that is instead enlarged at one side up to reach a part of a related groove (2) so as to house a related pressing means (16) therein. 9. Device as in claim 2, characterised in that the said plate means (6) are bound to each other by means of a bar (14) arranged transversal to them and inserted into corresponding openings (15) designed to act as a guide therefor.

Inventors: STOPPAZZINI BENITO, STOPPAZZINI, BENITO
Applicants: EMM SRL, E.M.M. S.R.L.
Application year: 1994
Main classification: D04B15
IPC codes: D04B15